Heredity and Evolution
In pea plants, the long-stem trait is dominant and the short-stern trait is recessive. Two pea plants were crossed, producing seeds that yielded 165 long-stem plants and 54 short-stem plants. The genotypes of the parent plants were most likely
Correct Answer: Option(b)
- The ratio of long stem plants to short stem plants among the progeny is 165:54 which means it has a ratio of 3:1. This ratio is possible if the parents are heterozygous in nature which after the cross will produce homozygous tall, heterozygous tall and homozygous dwarf offsprings.
- As the heterozygous offspring expresses the dominant allele, they will also be tall. This is a classic example of the monohybrid ratio that produces a ratio of 3:1 in the F2 generation of pure line parents.
So, the correct option is 'LI and LI'.